The frequency and the intensity of vibrations involving the backbone atoms in biological polymers are often quite sensitive to the conformation. Since these vibrations can be observed in the Raman effect in aqueous solution, laser Raman spectroscopy presents a new tool for studying the conformation of biological polymers and macromolecules in dilute solution. For polypeptides and proteins the sensitive vibrations are those of the peptide (amide group), for nucleic acids the sugar-phosphate group, and for membrane components containing fatty acid chains, the hydrocarbon chain vibrations. In addition there are low frequency motions which involve the motion of the molecule vibrating as a unit. From a study of these frequencies and intensities we hope to determine the structure of nucleic acids and proteins in aqueous solutions, relative to the structure in the crystal and solid phases where X-ray structure determination is possible. Of particular interest are the changes caused by interactions of macromolecules with small molecules and with each other.